New Delhi, Jan 6 (IANS): The Congress Tuesday said it was not yet clear whether Sunanda Pushkar, wife of party leader Shashi Tharoor, committed suicide or was murdered.

"Not yet certain whether Sunanda's death was suicide or murder," Congress spokesman Abhishek Singhvi said here.

That much was clear from what Delhi Police chief B.S. Bassi told the media, he said.

Bassi Tuesday said Pushkar was poisoned to death, but whether the poison was administered orally or injected into her body was still under investigation.

Based on the final medical report from AIIMS that called it a case of "unnatural death", Delhi Police Tuesday registered an FIR against unknown people under section 302 of the Indian Penal Code nearly a year after Pushkar was found dead in a luxury hotel in the capital.

In light of the latest revelation, Singhvi appealed for maintaining a sense of balance while refraining from giving it any sensational overtone.

He said the FIR was "just a beginning and not an end of a legal process".

"As police have also said it's not at all clear that whether it's a self-administered poison or outside-administered poison... every person has the full right to be treated as completely innocent unless and until a process of law goes beyond and further," the Congress leader added.

Tharoor was minister of state for human resource development in the Manmohan Singh government at the time his wife was found dead under mysterious circumstances at the Leela Palace hotel here Jan 17, 2014.